In filing cabinets, each drawer is typically guided by a pair of guide rails secured to either side of the drawer via rollers or slide shoes attached to the inner sides of the side panels of the cabinet main body. In addition to such means for guiding the in-and-out movement of the drawer, filing cabinets are typically equipped with a drawer control which allows the drawer to be selectively locked up among other possible functions. For security reasons, all the drawers are required to be locked up with a single operation. The drawer movement may be interlocked in such a manner that only one drawer can be pulled out at a time. Thereby, the need for massive counterweights to balance the shifting of the mass of the drawer can be eliminated. Additionally, a certain damping action is desirable which prevents the drawer to be inadvertently pulled out from the impact of the fully closing the drawer or from other impacts and vibrations, and absorbs the impact of the fully closing of the drawer.
Conventionally, there have been a number of proposals to achieve such functions, but as they were each directed to achieve only one or two of such functions. Therefore, when all of these functions are to be incorporated into a single cabinet, they had to be installed separately, and were inevitably complex and costly. For instance, Japanese utility model registration publication No. 3,008,337 discloses an arrangement which incorporates both a total lock up mechanism and a drawer interlock mechanism into a single mechanism.
A drawer damping mechanism can be achieved by providing a reversing spring mechanism including a resiliently supported catch which resiliently opposes the closing of the drawer immediately before it is fully closed, but resiliently pulls in the drawer when the drawer continues to move in the closing direction beyond a certain dead point. Once the drawer is fully closed, the resilient catch prevents the pulling out of the drawer unless a force greater than the resilient force acting on the catch is applied to the drawer. When the drawer is pulled out from the fully closed state with a sufficient force, the resilient catch is forced to move past the dead point, and, once this dead point is passed, assists the pulling out of the drawer. This drawer damping mechanism can therefore prevent an inadvertent opening of the drawer even when the drawer is forcibly closed, or when impacts and vibrations from other sources are applied to the drawer in addition to absorbing the impact of fully closing the drawer.
However, when the three functions are performed by two or more individual mechanisms, a substantially large number of component parts are required, and the amount of the assembly work correspondingly increases. These factors all contribute to the increase in the cost. Furthermore, because these three functions are required to be properly synchronized in operation, an inadequate assembling precision in one of the mechanisms may cause a general failure of the drawer movement.